Postoperative analgesic infusion device for orthopedics department

Abstract

The invention relates to the technical field of infusion instruments, in particular to a postoperative analgesic infusion device for the orthopedics department. The device comprises a medicament bag and a catheter, the catheter is provided with a filter part, the filter part comprises a tubular filter bag, a filter structure is installed in the filter part, a middle cavity is formed in the filter structure, and a floating piece is arranged in the middle cavity. The medical grade foamed silica gel umbrella-shaped display floating sheet with the density lower than that of the liquid medicine is adopted, the vortex effect formed by the conical middle cavity is matched, visual detection of the flowing state of the liquid medicine is achieved, when the liquid medicine flows through at a low speed, vortex formed in the middle cavity can push the display floating sheet to continuously and stably rotate, and the detection accuracy is improved. Relative movement of the indication mark can be observed through the light-transmitting material, and when abnormal conditions such as blockage of the pipeline occur, flowing of the liquid medicine is stopped, the display floating sheet statically suspends, the flowing condition of the liquid medicine can be judged, and clinical nursing efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of infusion device technology, and more specifically, to an analgesic infusion device for postoperative analgesia in orthopedic surgery. Background Technology

[0002] Orthopedic surgeries (such as joint replacement surgery and fracture reduction and fixation) are usually accompanied by significant trauma, postoperative wound pain that lasts for a long time, and are also prone to adverse stress responses such as vasoconstriction and muscle spasms. Therefore, postoperative analgesia is a key aspect of orthopedic clinical nursing. Among various analgesia methods, mechanical analgesia pumps are widely used in clinical practice due to their simple structure and the fact that they are mostly disposable. Their core working principle is to generate a constant thrust through a pre-compressed spring to push the drug reservoir to contract, thereby achieving precise and continuous infusion of the drug solution. Since orthopedic surgery often involves limb trauma and fixation, patients not only experience severe wound pain after surgery, but may also have limb movement disorders and limited ability to move or adjust the analgesia pump. If the analgesia pump moves with the patient's body, it is easy for the tubing to be pulled or twisted due to limb traction. Therefore, mechanical analgesia pumps are usually attached to the infusion stand at the head or bedside of the patient's bed to keep them in a relatively static state. In existing mechanical analgesia pumps, to ensure stable analgesia and avoid the risk of overdose, the infusion rate must be controlled within a low range of 0.5–2 mL / h. This results in extremely slow drug flow, making it difficult to visually observe the flow within the tubing. For first-time users, lacking relevant experience, the absence of drug flow may be misinterpreted as normal, affecting not only the patient's recovery experience but also potentially causing safety hazards due to abnormal drug infusion. Therefore, there is an urgent need for an analgesia infusion device for post-orthopedic surgery to solve these problems. Summary of the Invention

[0003] This invention provides an analgesic infusion device for post-orthopedic surgery, which uses double-layer filtration and a conical vortex to progressively intercept impurities in the medication solution. Furthermore, a display plate rotates stably with the medication flow to provide visual feedback, enabling real-time monitoring of the medication flow status in low-speed infusion scenarios. This solves the problems mentioned in the background art, namely: Existing mechanical analgesia pumps require slow infusion to control efficacy and avoid risks, making the flow of the drug solution difficult to observe with the naked eye. First-time users are prone to misinterpreting abnormalities.

[0004] To achieve the above object, the analgesic infusion device comprises a device body, the device body comprises a medicament capsule for storing a medicinal liquid and a catheter in communication with the medicament capsule, a pipeline regulating clamp is installed on the catheter downstream of the medicament capsule, an end of the catheter is provided with a PCA button, a filter is arranged on the catheter and located at the downstream end of the pipeline regulating clamp, the filter comprises a tubular filter capsule, a filter structure is installed inside the tubular filter capsule, and the filter structure separates the inner cavity of the tubular filter capsule into a buffer cavity and a liquid collecting cavity along the flow direction of the medicinal liquid; The filter structure is made of a light-transmitting medical material, a middle cavity is formed inside the filter structure, a visible floating piece is arranged inside the middle cavity, the density of the visible floating piece is less than that of the medicinal liquid, so that the visible floating piece can be suspended in the middle cavity, when the medicinal liquid flows at a preset low speed, a flow field driving the visible floating piece to rotate can be formed in the middle cavity, so that the visible floating piece generates a visual indication of continuous rotation, and when the medicinal liquid stops flowing, the rotation of the visible floating piece stops and the visible floating piece remains in a suspended and stationary state.

[0005] The filter structure comprises a secondary filter layer with a U-shaped cross section and a primary filter layer sleeved on the surface of the secondary filter layer, the extended outer wall of the primary filter layer is fixedly connected to the middle inner wall of the tubular filter capsule, the middle cavity is located between the primary filter layer and the secondary filter layer, and the inner walls of the primary filter layer and the secondary filter layer are in an inclined state, so that the inside of the middle cavity forms a tapered structure that is wide at the top and narrow at the bottom.

[0006] In the above technical solution, the nested double-layer filter layer and the tapered middle cavity realize step-by-step impurity interception and cyclone anti-blocking of the medicinal liquid, and the visible floating piece realizes stable suspension in the middle cavity, so that the functions of visual monitoring of medicinal liquid flow, impurity filtration, anti-blocking and exhaust pollution prevention are achieved in the low-speed infusion scene.

[0007] In addition, the visible floating piece is a hollow umbrella-shaped structure, the bottom end opening of the visible floating piece faces the liquid collecting cavity, the visible floating piece is made of a medical-grade foamed silica gel material, a balance bead is fixedly sealed in the middle part of the visible floating piece, and the balance bead can assist the visible floating piece to keep balance in the middle cavity.

[0008] The visible floating piece is a hollow umbrella-shaped structure with the bottom end opening facing the liquid collecting cavity, a medical-grade foamed silica gel material is selected to reduce the overall density to adapt to the suspension requirements of the medicinal liquid, a balance bead is fixedly sealed in the middle part of the visible floating piece, and the visible floating piece always keeps a balanced posture in the cyclone environment of the middle cavity, thereby providing a structural basis for stable rotation of the visible floating piece with the medicinal liquid, and ensuring the reliability of visual monitoring.

[0009] Compared with the prior art, the analgesic infusion device has the following beneficial effects: 1. The device for postoperative analgesia infusion in orthopedics, by adopting the medical grade foamed silica gel umbrella-shaped visible floating piece with lower density than the medical liquid, cooperating with the vortex effect formed by the tapered middle cavity, the visual detection of the flow state of the medical liquid is realized, specifically, when the medical liquid flows at low speed, the vortex formed in the middle cavity can push the visible floating piece to rotate continuously and stably, the relative movement of the indicating mark can be observed through the light-transmitting material, and the flow state of the medical liquid is quickly judged through the visual difference between the dynamic relative movement and the static relative stillness.

[0010] 2. The device for postoperative analgesia infusion in orthopedics, by adopting the double-layer filter structure composed of the primary filter layer and the secondary filter layer, cooperating with the tapered middle cavity with the upper width and the lower narrowness formed by the inclined inner wall of the filter structure, the filter precision of the medical liquid is improved, and the tapered middle cavity guides the medical liquid to form a stable rotational flow, the generation of the rotational flow can form a flexible flushing on the surface of the filter layer, the deposition of impurities on the surface of the filter membrane is reduced, and the continuity of the medical liquid infusion is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is the overall structure schematic diagram of the application; Figure 2 It is the structure schematic diagram of the filter piece in the application; Figure 3 It is the internal structure schematic diagram of the tubular filter bag in the application; Figure 4 It is the installation structure schematic diagram of the visible floating piece in the application; Figure 5 It is the running state schematic diagram of the visible floating piece in the application; Figure 6 It is the installation structure diagram of the balance bead in the visible floating piece in the application; Figure 7 It is the top view of the primary filter layer in the application under the cut state; Figure 8 It is the installation schematic diagram of the exhaust valve in the application.

[0012] The meanings of various signs in the figure are as follows: 1. Device body; 11. Medical agent bag; 12. Catheter; 13. Filter piece; 21. Tubular filter bag; 22. Filter structure; 23. Buffer cavity; 24. Liquid collecting cavity; 31. Secondary filter layer; 32. Primary filter layer; 33. Middle cavity; 34. Visible floating piece; 35. Balance bead; 36. Indicating mark; 37. Rib; 41. Exhaust valve; 42. Hydrophobic air filter membrane. DETAILED DESCRIPTION

[0013] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of the present application.

[0014] The existing mechanical analgesia pump needs to control the infusion rate of the drug solution in the low speed range of 0.5-2 mL / h to ensure smooth analgesia effect and avoid the risk of drug overdose, but the low speed causes the flow state of the drug solution to be difficult to be directly observed by naked eyes, and the patients who use the analgesia pump for the first time are easy to misjudge the abnormal condition of no flow of the drug solution as normal due to lack of experience, which not only affects the rehabilitation experience, but also may cause safety hazards. In view of this, the present application provides an analgesia infusion device for orthopedic postoperative patients, as shown in Figures 1-3 The device body 1 is composed of a drug cartridge 11 for storing the drug solution and a catheter 12 communicating with the drug cartridge 11. A pipeline adjusting clamp and a PCA button are sequentially installed on the catheter 12 along the flow direction of the drug solution. A filter 13 is arranged at the downstream end of the pipeline adjusting clamp. The filter 13 includes a tubular filter cartridge 21, and a filter structure 22 is assembled in the tubular filter cartridge 21. The filter structure 22 divides the inner cavity of the tubular filter cartridge 21 into a buffer cavity 23 and a liquid collecting cavity 24 along the flow direction of the drug solution. The filter structure 22 itself forms a middle cavity 33.

[0015] The filter structure 22 is specifically composed of a primary filter layer 32 and a secondary filter layer 31 arranged in a nested manner. The two layers are sequentially arranged along the flow direction of the drug solution to form a double-layer filter channel, so as to realize step-by-step interception of large-particle impurities and small-particle impurities in the drug solution. The middle cavity 33 is internally provided with a visible floating piece 34. When the drug solution flows at a low speed, the conical middle cavity 33 guides the drug solution to form a stable spiral downward flow. The tangential velocity component of the spiral flow generates a continuous tangential torque on the inclined surface of the visible floating piece 34, thereby driving the visible floating piece 34 to rotate. When the drug solution stops flowing or abnormal conditions such as blockage or bending of the pipeline occur, the rotation of the visible floating piece 34 synchronously stops and remains in a suspended and stationary state. The visual difference can realize the visual monitoring of the flow state of the drug solution.

[0016] The drug cartridge 11 has a working principle as known to those skilled in the art. The drug cartridge 11 is a flexible drug storage structure. A pre-compressed spring is arranged outside the drug cartridge 11. The constant elastic potential energy released by the spring continuously pushes the outer wall of the drug cartridge 11, so that the drug solution in the cartridge forms a stable pressure. The pressure is greater than the flow resistance of the catheter 12 and the filter structure 22. The drug solution is pushed to flow out of the drug cartridge 11 along the preset path, sequentially flows through the filter 13 and the pipeline adjusting clamp via the catheter 12, and finally realizes low-speed and accurate infusion through the output end controlled by the PCA button (using the existing technology, which is not described herein). The pre-compression amount and the elastic coefficient of the spring determine the basic infusion rate of the drug solution.

[0017] Due to the solubility limitation of analgesic agents themselves, and the production of residual filling process is easy, so the analgesic liquid is easy to contain drug crystal, pipeline debris and other impurities, and the infusion rate of mechanical analgesic pump is relatively slow, under low flow, impurities are easy to deposit, resulting in pipeline blockage or filter membrane failure, therefore, the analgesic pump will be provided with filter structure 22, such as Figure 3 As shown, the filter structure 22 in the tubular filter bag 21 includes a secondary filter layer 31 with a U-shaped cross section and a primary filter layer 32 sleeved on the surface of the secondary filter layer 31. The extended outer wall of the primary filter layer 32 is fixedly connected with the inner wall of the middle part of the tubular filter bag 21, so that the primary filter layer 32 and the secondary filter layer 31 form a nested structure, and the gap between them constitutes a middle cavity 33, which provides installation and movement space for the visible floating piece 34. The primary filter layer 32 and the secondary filter layer 31 are arranged in sequence along the flow direction of the liquid medicine, forming a double-layer filter channel. The liquid medicine is first intercepted by the primary filter layer 32 to remove large particles, and then passes through the secondary filter layer 31 to remove small particles, effectively improving the purity of the liquid medicine. The nested structure fixes the filter path, effectively reducing the risk of filter failure caused by liquid bypass flow. In addition, the inner walls of the primary filter layer 32 and the secondary filter layer 31 are inclined, so that the inside of the middle cavity 33 is a tapered structure with a wide upper part and a narrow lower part. Figure 4 As shown in the figure, when the liquid medicine flows from the buffer cavity 23 into the wide end of the middle cavity 33, it flows along the inclined inner wall to the narrow end. Due to the tapered structure, the space cross-sectional area gradually decreases along the flow direction of the liquid medicine, and the flow rate of the liquid medicine changes along the path. At the same time, the inclined inner wall produces a continuous tangential guiding effect on the liquid medicine, so that the liquid medicine forms a circumferential motion component along the circumference of the middle cavity 33 during the flow process, and then synthesizes a stable spiral downward flow. The tangential fluid impact force generated by the flow acts on the surface of the filter layer, which can prevent the impurities in the liquid medicine from adhering and depositing on the surface of the filter membrane, and at the same time, it can strip the small impurities that have been preliminarily adhered from the surface of the filter membrane and flow into the liquid collecting cavity 24 together with the spiral flow, thereby reducing the accumulation of impurities on the surface of the filter layer and reducing the risk of filter membrane blockage.

[0018] The primary filter layer 32 and the secondary filter layer 31 described above are made of light-transmitting medical materials that meet the ISO 10993 biocompatibility standard. Specifically, medical-grade polycarbonate and medical-grade polymethyl methacrylate can be selected. Such materials have high light transmittance, allowing clear observation of the inside of the middle cavity 33. At the same time, such materials have good chemical corrosion resistance and can withstand long-term contact with postoperative analgesic liquids (such as opioid drugs and non-steroidal anti-inflammatory drugs) without degradation of the material, excessive leaching, and other problems.

[0019] It should be noted that the extended end of the primary filter layer 32 is not a filter material. The extended end of the primary filter layer 32 is used to assist in its fixation.

[0020] Referring to Figure 5 and in combination with Figure 6 shown, the visible floating piece 34 is a hollow umbrella-shaped structure with its bottom end opening facing the liquid collection cavity 24. The visible floating piece 34 is made of foamed silica gel which meets the medical biocompatibility standards as the base material, and is processed by a medical-grade physical foaming process. During the foaming process, the foaming agent generates micro-bubbles in the silica gel base material to form a closed-pore porous structure with a pore diameter controlled at 50-100 μm, and the pores are uniformly distributed in the entire base material without local concentration or hollow defects. The porous structure and the hollow structure of the visible floating piece 34 form a material reduction synergistic effect, so that the overall density of the visible floating piece 34 is reduced to 0.7-0.8 g / cm 3 , while the density of the orthopedic postoperative analgesic liquid is usually 1.0-1.05 g / cm 3 . Finally, the density of the visible floating piece 34 is lower than that of the liquid, which meets the basic physical conditions for its suspension in the middle cavity 33. At the same time, the closed-pore structure can avoid the penetration of the liquid into the pores to cause the density of the visible floating piece 34 to change, ensuring the long-term stability of the suspension state. The middle region of the visible floating piece 34 is fixed with a balance bead 35 made of medical-grade glass microbeads through a glue sealing process, so that the center of gravity of the visible floating piece 34 is concentrated on the central axis, which can effectively offset the lateral thrust generated when the liquid flows, reducing the situation that the visible floating piece 34 is tilted, turned on its side or adheres to the surface of the primary filter layer 32 and the secondary filter layer 31 in the rotational flow. The setting of the bottom end opening facing the liquid collection cavity 24 can adapt to the spiral downward flow formed by the tapered structure of the middle cavity 33, reducing the problem of increased flow resistance or rotational disorder caused by the conflict between the opening direction and the flow direction.

[0021] Back to Figure 5, the bottom end of the apparent floating piece 34 is open towards the liquid collecting cavity 24, and is kept in a horizontal suspended posture by the middle balancing ball 35, and does not adhere to the inner wall of the filter layer. When the liquid medicine flows through the middle cavity 33 at a low speed of 0.5-2 mL / h, the conical structure guides the liquid medicine to form a stable vortex along the cavity wall, which has both axial (downward) and tangential (along the circumference of the cavity wall) velocity components. The tangential component provides the core power for the rotation of the apparent floating piece 34. The tangential fluid of the vortex passes through the apparent floating piece 34 and vertically impacts the lower surface of the apparent floating piece 34 (the lower surface is the force receiving surface because the surface of the apparent floating piece 34 is downwardly inclined). Due to the inclination angle of the surface of the apparent floating piece 34, the tangential fluid generates a circumferential force (i.e. tangential thrust) on the surface of the apparent floating piece 34. The tangential thrust forms a continuous torque around the central axis of the apparent floating piece 34. The low density of the apparent floating piece 34 makes the buoyancy and gravity of the apparent floating piece 34 balanced, and the impact force of the axial fluid is offset by the buoyancy, without up-down displacement interference, and only the tangential torque causes the rotation of the apparent floating piece 34. At the same time, the middle balancing ball 35 ensures that the center of gravity of the apparent floating piece 34 is concentrated on the central axis, avoiding lateral inclination caused by vortex impact, making the force on each point of the annular fin uniform, and the torque stable, thereby realizing the continuous rotation of the apparent floating piece 34 during the delivery of the medicament.

[0022] It should be noted that in the initial stage, due to the possible slight flow field unevenness when the liquid medicine flows through the filter membrane, the initial circumferential direction of the vortex flow may have slight uncertainty (may be clockwise or counterclockwise), which causes the initial tangential thrust on the apparent floating piece 34 to be random. However, once the apparent floating piece 34 starts to rotate, a flow field following locking effect is formed. The apparent floating piece 34 rotates to form a synchronous local following flow field with the surrounding liquid medicine, which strengthens the circumferential direction of the initial vortex flow, so that the tangential component of the vortex flow of the subsequent liquid medicine entering the middle cavity 33 is consistent with the rotation direction of the apparent floating piece 34. At the same time, the inclination angle of the surface of the apparent floating piece 34 is fixed, and once it rotates in a certain direction, the relative motion trajectory of the surface of the apparent floating piece 34 and the vortex flow is fixed, and the tangential thrust always acts in the rotation direction. For example: the initial counterclockwise rotation is caused by the slight difference in flow field, the relative inclined surface of the surface of the apparent floating piece 34 and the vortex flow is forced in a fixed direction, and the subsequent vortex flow is guided by the local flow field driven by the apparent floating piece 34 to continuously provide counterclockwise tangential thrust. In addition, the middle balancing ball 35 can ensure that the center of gravity of the apparent floating piece 34 is concentrated on the central axis, reducing the deviation of the force receiving direction caused by inclination during rotation.

[0023] When the liquid medicine flows through the middle cavity 33 at a preset low speed, the operation of the visible floating piece 34 in the middle cavity 33 can be clearly observed through the light-transmitting filter structure 22, and it is directly observed whether the liquid medicine flows normally. When the liquid medicine stops flowing or the pipeline is blocked, bent or has other abnormal conditions, the rotation of the visible floating piece 34 is synchronously stopped and remains in a suspended and stationary state. Through the visual difference of whether the rotation is in a single direction, the liquid medicine flow state can be quickly judged without additional detection tools, real-time monitoring of infusion abnormalities is realized, and the needs of the orthopedic postoperative clinical nursing scene are adapted.

[0024] As Figure 4 A partition rib 37 (the number is not less than two) is arranged on the inner wall of the middle cavity 33. The partition rib 37 is uniformly distributed along the circumferential direction of the middle cavity 33, and has a ring structure coaxial with the middle cavity 33. The material of the partition rib 37 is consistent with the filter structure 22, and is a light-transmitting medical material. The edge of the partition rib 37 is treated with a round corner. The partition rib 37 forms a limit for the visible floating piece 34 through the ring structure and the uniform distribution in the circumferential direction. When the visible floating piece 34 is suspended and rotated or is radially deviated and tilted by the impact of the liquid flow field, the radial deviation range of the visible floating piece 34 can be limited by the radial blocking action of the ring structure, so that the visible floating piece 34 is prevented from adhering to the surface of the primary filter layer 32 or the secondary filter layer 31. The inclination and lateral turning amplitude of the visible floating piece 34 are further constrained by the multiple-point support uniformly distributed in the circumferential direction. The balance bead 35 in the middle part of the visible floating piece 34 ensures that the visible floating piece 34 always maintains a horizontal posture in the middle part of the middle cavity 33. The round corner treatment and the flexible material characteristics prevent the partition rib 37 from generating rigid friction when it contacts the visible floating piece 34, so that the surface structure of the visible floating piece 34 is not damaged, the rotation movement of the visible floating piece 34 is not hindered, and the flow field integrity of the spiral rotational flow in the middle cavity 33 is not damaged, so that the smooth flow of the liquid medicine and the stable rotation of the visible floating piece 34 are ensured.

[0025] As Figure 7As shown, an indication mark 36 is arranged on the umbrella surface outer surface of the developing float 34, and an indication mark 36 is also arranged on the surface of the primary filter layer 32. The indication mark 36 is firmly combined with the respective substrate by a heat pressing or curing process using a medical-grade chemical corrosion-resistant ink, without the risk of falling off or dissolving out. The indication mark 36 is shaped as a strip (the mark position avoids the rotating axis of the developing float 34 and the filter hole area of the primary filter layer 32, without affecting the liquid flow and filtering function). When the developing float 34 rotates in the middle cavity 33, the indication mark 36 on the developing float 34 moves in a circular motion around the central axis, and the indication mark 36 on the primary filter layer 32 remains fixed. The two sets of marks form a continuous relative displacement in the circumferential direction. The color contrast design makes the relative motion track clear and distinguishable, and the human eye can quickly capture the dynamic change without relying on additional tools. When the liquid flows normally, the relative motion continues, and the rotating state of the developing float 34 and the normal flow of the liquid can be directly confirmed through the dynamic state. When the liquid stops flowing or there is an abnormal situation such as blockage or bending of the pipeline, the developing float 34 stops rotating synchronously, and the two sets of marks remain relatively stationary. The visual difference between dynamic relative motion and static relative stillness realizes the quick judgment of the liquid flow state.

[0026] For example, a black strip-shaped indication mark 36 is arranged on the umbrella surface outer surface of the developing float 34 in the circumferential direction, and a white strip-shaped indication mark 36 is arranged on the surface of the primary filter layer 32. The size of the indication mark 36 on the developing float 34 is consistent with that of the indication mark 36 on the primary filter layer 32. When the liquid normally flows to push the developing float 34 to rotate, the black mark on the developing float 34 continuously rotates around the central axis with the umbrella surface, and forms an alternating and interlaced relative motion with the fixed white mark on the primary filter layer 32. From the outside of the transparent and filtering structure 22, the dynamic switching of the black mark and the white mark can be clearly seen, and the normal flow state of the liquid can be directly confirmed.

[0027] The top of the tubular filter capsule 21 is tightly wrapped around the outer wall of the catheter 12. The output end of the catheter 12 penetrates the top of the tubular filter capsule 21 and extends into the internal filter cavity. There is no gap at the connection site, ensuring that all the liquid output from the catheter 12 enters the internal filter cavity of the tubular filter capsule 21, while guaranteeing the flow path sealing to prevent air from entering the buffer cavity 23 from the connection. A circular exhaust port is formed in the center area of the top of the buffer cavity 23. The inner diameter of the exhaust port is adapted to the size of the connection interface of the exhaust valve 41. The exhaust valve 41 is installed at the exhaust port using a buckle type sealing structure (using existing technology, which is not described here). In the closed state, the exhaust port is completely sealed. In the open state, it can connect the inside of the buffer cavity 23 with the external environment. This design can actively open the exhaust valve 41 before or during the infusion of the liquid to exhaust the air remaining in the device body 1. Referring to Figure 8As shown, the exhaust port is close to the opening end of the buffer cavity 23, and the hydrophobic air filter membrane 42 is fixed by the pressing ring. The hydrophobic air filter membrane 42 is made of medical-grade polytetrafluoroethylene material (the pore size specification can be 0.22-0.45 μm), the hydrophobic surface of the hydrophobic air filter membrane 42 faces the inside of the buffer cavity 23, and the hydrophilic surface faces the side of the exhaust valve 41. The air in the buffer cavity 23 is allowed to pass through and be discharged through the exhaust valve 41, while the drug liquid is prevented from penetrating due to the hydrophobic property, avoiding drug liquid leakage during the exhaust process. The pore size of the filter membrane can filter dust, microorganisms and other particles in the air, preventing external pollutants from entering the buffer cavity 23 through the exhaust port to contaminate the drug liquid. The exhaust valve 41 can maintain the sealing state of the buffer cavity 23 after being closed, ensuring the cleanliness and smoothness of the drug liquid infusion.

[0028] Working principle: First, the analgesic liquid is delivered to the tubular filter capsule 21 through the catheter 12. The top of the tubular filter capsule 21 is tightly wrapped and sealed with the outer wall of the catheter 12 to ensure that all the drug liquid enters the filter cavity without leakage or air infiltration. The exhaust valve 41 at the top of the buffer cavity 23 can be opened before or during infusion to exhaust the residual air in the buffer cavity 23. Then, the drug liquid flows through the double-layer filter channel formed by the primary filter layer 32 and the secondary filter layer 31 in sequence. The primary filter layer 32 first intercepts large particles, and the secondary filter layer 31 then traps small particles, improving the purity of the drug liquid. The inclined inner walls of the primary filter layer 32 and the secondary filter layer 31 form a tapered cavity 33 with a wide top and a narrow bottom. After the drug liquid flows from the buffer cavity 23 into the wide end of the cavity 33, it flows along the inclined inner wall to the narrow end, forming a stable spiral downward flow due to the gradual change of the space cross-sectional area and the tangential guiding effect. The apparent floating piece 34 in the cavity 33 realizes the suspended state with a density lower than the drug liquid due to the closed-cell porous structure and hollow umbrella-shaped design of the medical-grade foamed silica gel. At the same time, the spiral flow formed by the drug liquid has a tangential velocity component, which vertically impacts the inclined lower surface of the apparent floating piece 34 and generates a continuous tangential torque, driving the apparent floating piece 34 to rotate. The apparent floating piece 34 and the color-contrasted indicator 36 on the primary filter layer 32 rotate together, forming a continuous relative motion, which can be directly observed through the light-transmitting filter structure 22. Finally, the filtered pure drug liquid is output through the liquid collection cavity 24, realizing low-speed and precise infusion. If the drug liquid flows normally, the apparent floating piece 34 rotates continuously in a single direction, and the indicator 36 moves dynamically relative to the apparent floating piece 34. If the pipeline is blocked, bent or the drug liquid stops flowing, the apparent floating piece 34 is synchronized and stationary. By visually distinguishing the infusion state, the drug liquid filtration, anti-blocking and flow state visualization monitoring are cooperatively worked.

[0029] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. Orthopedic postoperative analgesic infusion device, comprising a device body (1) comprising a medicine bag (11) for storing medicinal liquid and a catheter (12) in communication with the medicine bag (11), a pipeline regulating clamp being installed on the catheter (12) downstream of the medicine bag (11), and a PCA button being provided at the end of the catheter (12), characterized in that: a filter (13) is arranged on the catheter (12) and located at the downstream end of the pipeline regulating clamp, the filter (13) comprising a tubular filter bag (21) with a filter structure (22) installed inside, the filter structure (22) separating the inner cavity of the tubular filter bag (21) into a buffer cavity (23) and a liquid collecting cavity (24) along the flow direction of the medicinal liquid; the filter structure (22) is made of a light-transmitting medical material, a middle cavity (33) is formed inside the filter structure (22), a visible floating piece (34) is arranged inside the middle cavity (33), the density of the visible floating piece (34) is less than that of the medicinal liquid, so that the visible floating piece (34) can be suspended in the middle cavity (33), when the medicinal liquid flows at a preset low speed, a flow field driving the visible floating piece (34) to rotate can be formed in the middle cavity (33), so that the visible floating piece (34) produces a visual indication of continuous rotation, when the medicinal liquid stops flowing, the rotation of the visible floating piece (34) stops and remains in a suspended stationary state. the filter structure (22) comprises a secondary filter layer (31) with a U-shaped cross section and a primary filter layer (32) sleeved on the surface of the secondary filter layer (31), the extended outer wall of the primary filter layer (32) is fixedly connected to the middle inner wall of the tubular filter bag (21), and the middle cavity (33) is located between the primary filter layer (32) and the secondary filter layer (31). the inner walls of the primary filter layer (32) and the secondary filter layer (31) are both in an inclined state, so that the inside of the middle cavity (33) forms a tapered structure with a wide upper part and a narrow lower part.

2. The analgesic infusion device for use after orthopedic surgery according to claim 1, characterized in that: the visible floating piece (34) is a hollow umbrella-shaped structure, the bottom opening of the visible floating piece (34) faces the liquid collecting cavity (24), and the visible floating piece (34) is made of medical-grade foamed silica gel.

3. The analgesic infusion device for use after orthopedic surgery according to claim 2, characterized in that: a balance bead (35) is fixedly sealed in the middle part of the visible floating piece (34), and the balance bead (35) can help the visible floating piece (34) to maintain balance in the middle cavity (33).

4. The analgesic infusion device for post-operative orthopedic procedures of claim 1, wherein: at least two circumferentially spaced apart separation ribs (37) are protrudingly arranged on the inner wall of the middle cavity (33), and the separation ribs (37) are annular structures for flexibly limiting the visible floating piece (34) when it is suspended.

5. The analgesic infusion device for use after orthopedic surgery of claim 1, wherein: the umbrella surface of the visible floating piece (34) and the tapered inner surface of the primary filter layer (32) are correspondingly provided with color-contrasting indication marks (36).

6. The analgesic infusion device for use after orthopedic surgery of claim 1, wherein: when the visible floating piece (34) rotates, the two indication marks (36) produce relative motion to enhance the visual recognition.

7. The analgesic infusion device for post-operative orthopedic procedures of claim 2, wherein: the top of the tubular filter bag (21) is in a state of wrapping the catheter (12), an exhaust port is arranged at the top of the buffer cavity (23), and an exhaust valve (41) is sealingly installed on the exhaust port.

8. The analgesic infusion device for use after orthopedic surgery according to claim 7, characterized in that: ​ 9. The analgesic infusion device for post-operative orthopedic procedures of claim 1, wherein: ​ 10. The analgesic infusion device for use after orthopedic surgery according to claim 9, characterized in that: The air exhaust port is close to the inner side opening of the buffer cavity (23), and is provided with a hydrophobic air filter membrane (42).

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